package com.zhou.servlet;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.HttpCookie;
import java.net.URLEncoder;
import java.util.Set;

public class FileServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//        要获取下载文件的路径
        String filepath = "E:\\project\\javaweb02servlet\\response\\target\\response\\WEB-INF\\classes\\周.png";
        System.out.println("下载文件的路径:" + filepath);
//        下载的文件名是啥？
        String fileName = filepath.substring(filepath.lastIndexOf("\\") + 1);
        System.out.println(fileName);
//        设置想办法让浏览器能够支持下载我们需要的东西
        resp.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName,"UTF-8"));
//        获取下载文件的输入流
        FileInputStream in = new FileInputStream(filepath);
//        创建缓冲区
        int len = 0;
        byte[] buffer = new byte[1024];
//        获取OutputStream对象
        ServletOutputStream out = resp.getOutputStream();
//        将FileOutputStream流写入到bufer缓冲区,使用OutputStream将缓冲区中的数据输出到客户端！
        while((len = in.read(buffer)) > 0){
            out.write(buffer, 0, len);
        }
        in.close();
        out.close();
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        super.doGet(req, resp);
    }
}
